Success!

by Mark Lemmon

March 21, 2008 - The characterization dry run ended with a successful and on-time delivery of a scoopful of surface material to TEGA door number 4 on sol 7. The last elements in the so-called “critical path” to characterization were to perform a touch test with the robotic arm (sol 5), perform a test dig and sample acquisition just to the right of the touch on sol 6, and acquire a sample and deliver it to TEGA on sol 7.

Along the way, we demonstrated that TEGA was ready for the sample with a sol to spare. MECA is also ready for a sample to analyze -- really a pair, one for the microscopes and one for the chemistry cell. Our initial site survey, a low resolution black and white panorama, was completed by SSI on sol 3 and mostly downlinked by sol 6 (“mostly” because some small pieces get lost in space, and will have to be sent by the lander again). We have also obtained imaging documentation of the sample, meaning that we took images with SSI’s visible and infrared filter of the sample and the mini-trench left behind, and we also obtained color images of the sample in the scoop.

In real operations, we would now be ready to use the lander to accomplish the best science and exploration the team could plan. There are many options for the next sols, and the path taken will depend on the exact situation. We have a number of things that need to be done to go beyond characterization and really get started with the science. For instance, we delivered a sample to TEGA, but we haven’t used TEGA to analyze the atmosphere. If TEGA analyzes the surface before the atmosphere, the later measurements will not be as effective as they could be. So, we’d like to delay the soil analysis until after we spend a sol on the atmospheric analysis. Another thing we’d like to do soon, of course, is to get samples to MECA and to use MECA’s TECP to analyze soil. We’ve just started our color panorama of the landing site -- I for one would like to see this done soon. And the thing I’m most excited to do is find out one key thing about our site that we do not know yet -- where is the ice -- and I’d like to see a test trench. The cool result of characterization is that we started with unknowns -- a lander in unknown condition sitting for its first time in a site we had little specific information on -- and we finish with the ability to debate over nearly the full range of things we can do with that lander -- understanding the weather and how temperatures impact the lander, and how it interacts with the surface layer of the small piece of Mars in front of us.

Below is a small sample of what we’ve seen in our simulated Mars, the Payload Interoperability Testbed (PIT). The first image is a stereographic projection (sort of a fish eye view) looking down on the lander and out past the horizon. It shows the PIT floor and walls, as well as the test lander -- notice that in order to come even close to Mars like lighting, there are several lights in the panorama, resulting in a few bright spots.

The image below is a vertical projection of the workspace as it would be seen from above. The dig test area was just to the right of the small rocks in the center (see image 3).

The next image shows the test touch (left) and test dig (right) results in a mosaicked pair of SSI images. The pile of debris from the dig is in the center of the right hand edge of the image. The shadow across the image was cast by the robotic arm.